Category Archives: High Altitude

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Lost, Stranded, and Hungry in the Mountains of Western Colorado? A Mini Guide to Edible Plants

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From backpacking and camping to skiing and snowboarding, there are plenty of activities outdoors in the Colorado high country. If you find yourself wandering around and lost without food in the mountains, there are several wild plants that you can eat. 

However, before you consume the delectable greens, there are a few precautions to take.

Moose shopping
  • Do not eat any wild plants unless you can positively identify them. There are iOS and Android apps that you can download prior to your hike to help distinguish plants, such as PictureThis and NatureID. 
  • Be aware of environmental factors such as pollution or animal waste. Avoid popular wild animal gathering areas.
  • Make sure you’re not allergic to the plant by rubbing it against your skin and observing for a reaction. If so, do not eat the plant. Before ingesting a large quantity, eat a small amount and check for a reaction. 

It may be difficult to cook if you did not come prepared with a portable stove, pots, and water, which could limit ways to enjoy vegetation. Here is a list of edible plants, how to identify them, where can they be found, and which part you can eat.

Wild plants

Dandelions (Taraxacum officinale): yellow ray florets that spread outward from center with toothy, deep-notched, hairless basal leaves and hollow stems. They can be found everywhere and anywhere. Every part of the dandelion plant is edible including the leaves and roots.

Yellow-green hemispheres bud in a bunch from green stems with pine needle-like leaves.

Pineapple Weed/ Wild Chamomile (Matricaria discoidea): the flower heads are cone-shaped and yellowish-green and do not have petals. Often found near walking paths and roadsides, harvest away from disturbed, polluted areas. If you’re feeling anxious about being lost, pineapple weed promotes  relaxation and sleep and serves as a  digestive aid.

Fireweed (Epilobium angustifolium): vibrant fuchsia flowers. Grows in disturbed areas and near recent burn zones. Eat the leaves when they are young as  adult leaves can stupefy you. Young shoot tips and roots are also edible. 

Wild onions (Allium cernuum): look for pink, lavender to white flowers with a strong scent of onion. They grow in the subalpine terrain and are found on moist hillsides and meadows. Caution: do not confuse with death camas. If it doesn’t smell like an onion and has pink flowers, it is not likely an onion.

Cattails (Typha latifolia or Typha angustifolia): typically 5-10 feet tall. Mature flower stalks resemble the tail of a cat. Grow by creek, river, ponds, and lakes. This whole plant is edible, from the top to the roots. Select from pollution-free areas as it is known to absorb toxins in the surrounding water.

Wild berries:

Wild strawberries (Fragaria virginiana): they are tiny compared to  store-bought. Can be identified by their blue-green leaves; small cluster of white flowers with a yellow center; and slightly hairy, long and slender red stems.

Huckleberries (Vaccinium spp): They grow in the high mountain acidic soil and flourish in the forest grounds underneath small, oval-shaped, pointed leaves. They resemble blueberries and have a distinguishable “crown” structure at the bottom of the berry. They can be red, maroon, dark blue, powder-blue, or purple-blue to almost black, and they range from translucent to opaque.

Deep blue berries stand out against bright red and green, waxy leaves.

Oregon grapes (Mahonia aquifolium): powder-blue berries, resembling juniper berries or blueberries, with spiny leaves similar to hollies that may have reddish tints.

Fun fact: The roots and bark of the plant contain a compound called berberine. Berberine has antimicrobial, antiviral, antifungal, and antibiotic properties.

Mushrooms

Brown whole and halved mushrooms lie on a green table with ridged, sponge-looking caps.

True morels (Morchella spp.): cone-shaped top with lots of deep crevices resembling a sponge. They will be hollow inside. A false morel will have a similar appearance on the outside but will not be hollow on the inside and are toxic. Morels are commonly found at the edge of forested areas where ash, aspen, elm, and oak trees live. Dead trees (forest wildfires) and old apple orchards are prime spots for morels.

Short, stubby mushrooms with white stems and brown camps stand in a row growing over grass.

Porcini (Boletus edulis): brown-capped mushrooms with thick, white stalks. Found at  high elevations of 10,500 and 11,200 ft in  areas with monsoon rains and sustained summer heat.

There are many more edible plants, flowers, berries, and mushrooms in the mountains. These are just 10 that can be easily identifiable and common in the Western Colorado landscapes. I recommend trying out the apps listed above and reading “Wild Edible Plants of Colorado” by Charles W. Kane, which includes 58 plants from various regions, each with details of use and preparation. Hopefully this post made you feel more prepared for your next adventure. 

Resources:

Davis, E., 2022. Fall plant tour: Frisco, CO | Wild Food Girl. [online] Wildfoodgirl.com. Available at: <https://wildfoodgirl.com/2012/eleven-edible-wild-plants-from-frisco-trailhead/> [Accessed 10 July 2022].

McGuire, P., 2022. 8 Delicious Foods to Forage in Colorado | Wild Berries…. [online] Uncovercolorado.com. Available at: <https://www.uncovercolorado.com/foraging-for-food-in-colorado/> [Accessed 10 July2022].

Rmhp.org. 2022. Edible Plants On The Western Slope | RMHP Blog. [online] Available at: <https://www.rmhp.org/blog/2020/march/foraging-for-edible-plants> [Accessed 10 July 2022].

Lifescapecolorado.com. 2022. [online] Available at: <https://lifescapecolorado.com/2014/01/edible-plants-of-colorado/> [Accessed 10 July 2022].

Pfaf.org. 2022. Plant Search Result. [online] Available at: <https://pfaf.org/user/DatabaseSearhResult.aspx> [Accessed 10 July 2022].

Cindy Hinh is a second-year Physician Assistant student at Red Rocks Community College in Arvada, CO. She grew up in southern Louisiana and received her undergraduate degree in Biology from Louisiana State University. Prior to PA school, she was a medical scribe in the emergency department and an urgent care tech. In her free time, she enjoys baking, cooking, going on food adventures, hiking, and spending time with family and friends.

Acclimation, Exposure, Health, High Altitude, High Altitude Training & Fitness

Non-Freezing Cold Injury

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Eighteen-year-old, NorAm skier, NCAA Division I Rugby player, and lover of the outdoors, presents to the clinic complaining of cold, painful hands. She states hands always feel cold, and in cold weather they are extremely painful. Blood tests to rule out vascular disease were normal. What could be the cause of this?

Normally, in cold weather our bodies work to keep essential organs functioning. Skin is not considered essential. When exposed to cold, blood vessels constrict, decreasing blood flow to the skin. Because the metabolic demand of our skin is low, more important organs like our heart and brain need the blood flow. Paradoxically, exposure to cooler temperatures like those below 15 degrees Celsius or 59 degrees Fahrenheit can cause cold-induced vasodilation. This allows blood to flow to the skin to help prevent more serious injury or frostbite. The vasodilation cycles in 5- to 10-minute intervals.

Nonfreezing cold injury (NFCI) occurs when tissues are damaged due to prolonged cooling exposure, but not freezing temperatures. NFCI is due to exposure of the extremities to temperatures around 0 to 15°C or 32 to 59°F, commonly the hands and feet. Current theory is that NFCI is due to a combination of vascular and neural dysfunction. With prolonged vasoconstriction, the skin experiences reduced blood flow with a neurological component influencing the damage as well.

Some patients living in cold environments like the Inuit, Sami people, and Nordic fisherman have a larger cold-induced vasodilation response and more rapid cycling. This is thought to decrease their risk of NFCI. Is it possible that patients who develop NFCI have a smaller and slower cycling of their cold-induced vasodilation? Could this be the issue with our patient with NFCI?  Further research is needed to learn more about NFCI and find better ways to treat it.

What we do know is there are 4 Stages of NFCI:

Stage 1: During the cold exposure – Loss of sensation, numbness, clumsiness. Usually painless unless rewarming is attempted.

Stage 2: Following cold exposure – occurs during and after rewarming. Skin can develop a mottled pale blue-like color, area continues to feel cold and numb, possible swelling. Usually lasts a few hours to several days.

Stage 3: Hyperemia – affected area becomes red and painful. Begins suddenly and lasts for several days to weeks.

Stage 4: Following hyperemia – affected areas appear normal but are hypersensitive to the cold. Areas may remain cold even after short exposure to the cold. This stage can last for weeks to years.

Mountains covered in pine forests reach up past tree line toward a deep blue sky spotted with fluffy white cumulous clouds over two people in bikinis standing on paddle boards reflected with the clouds in the dark water below them.

Outdoor paddle sports like kayaking and canoeing put patients at greatest risk due to the continual exposure to the cold, wet environment. It was thought that in order to have NFCI, one had to be exposed to both cold and wet environments. However, it has been shown that this is not always the case. Like in our patient, exposure to just cold environment can trigger the syndrome. Our 18-year-old patient is an avid skier and spends most of the winter on the mountain. It was also noted that she enjoys paddleboarding and kayaking, which were recognized as triggers for the hand pain. We are unable to determine exactly what caused our patient to develop this syndrome. But we do know it affects their life significantly.

 We choose to live in the mountains because of the things we love. Whether it is hiking, biking, skiing, kayaking, paddleboarding, or the hundreds of other activities offered in this area, we are at risk of NFCI. Currently, there is no good treatment for this syndrome. Prevention is  best. The purpose of this blog is to share information about staying healthy at high altitude. Sharing this information on the stages of NFCI with friends and family will help prevent this painful, debilitating syndrome.

Resources

Nonfreezing cold water (trench foot) and warm water immersion injuries. UpToDate. https://www.uptodate.com/contents/nonfreezing-cold-water-trench-foot-and-warm-water-immersion-injuries/print#:~:text=Nonfreezing%20cold%20injury%20%E2%80%94%20NFCI%20is,to%2059%C2%B0F)%20conditions. Accessed July 14, 2022.

Oakley B, Brown HL, Johnson N, Bainbridge C. Nonfreezing cold injury and cold intolerance in Paddlesport. Wilderness & Environmental Medicine. 2022;33(2):187-196. doi:10.1016/j.wem.2022.03.003

Rachel Cole is a Physician Assistant Student at Red Rocks Community College in Denver, Colorado. She originally grew up in Salt Lake City, Utah, where she learned to love the outdoors. She studied Biology at Western Colorado University in Gunnison, Colorado prior to PA school. She played soccer for the college and fell in love with Colorado and small mountain towns. When she is not studying for school, she enjoys skiing, hiking, backpacking, fishing, waterskiing, canyoneering, and any other activities that get her outside. After graduation she hopes to practice family medicine in a rural community in the mountains.

Acclimation, Child Growth & Development, Health, High Altitude, Medicine

Beneficial Effects of Chronic Hypoxia

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Living in Summit County, Colorado has its perks – residents are within a 20 to 40 minute drive to five world class ski resorts, and some of the most beautiful Rocky Mountain trail systems are accessible right out our back door. With the endless opportunities drawing residents outdoors to partake in physical activity, it comes as no surprise that Summit County is considered one of the healthiest communities in the country. However, there may be more than meets the eye when it comes to explaining this, as it also has something to do with the thin air.

As a Summit County native, you have likely heard the term “hypoxia” or “hypoxemia” mentioned a time or two. So what does this mean? Simply put, these words describe the physiological condition that occurs when there is a deficiency in the amount of oxygen in the blood, resulting in decreased oxygen supply to the body’s tissues. When this occurs in the acute setting, it may result in symptoms such as headache, fatigue, nausea, and vomiting. These are common symptoms experienced by those with altitude illness, also known as acute mountain sickness. While these symptoms can cause extreme discomfort and may put a huge damper on a mountain vacation, they are not usually life threatening. However, in a small number of people, development of more serious conditions such as a high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE) can occur. The treatment for all conditions related to altitude illness is oxygen, whether via return to lower elevations or by a portable oxygen concentrator that allows you to stay where you are. While altitude illness generally affects those who rapidly travel from sea level to our elevation, it has also been known to affect residents returning home to altitude, usually after a period of two or more weeks away. In a very small subset it can occur after a period of only a day or two. This generally occurs in those with a preexisting illness, where altitude exacerbates the condition.

While the acute effects of altitude can clearly have detrimental effects on one’s physical well-being, there is emerging research demonstrating that chronic hypoxia may actually come with several health benefits. Long time Summit County business owner and community pediatrician, Dr. Chris Ebert-Santos of Ebert Family Clinic in Frisco, has spent quite some time studying the effects of chronic high-altitude exposure, and recently attended and presented at the Chronic Hypoxia Symposium in La Paz, Bolivia, the highest capital city in the world.

It is important to first understand the adaptations that occur in our bodies as a result of long-term hypoxia. The ability to maintain oxygen balance is essential to our survival.

So how do those of us living in a place where each breath we take contains about ⅓ fewer oxygen molecules survive?

Simply put, we beef up our ability to transport oxygen throughout our body. To do this, our bodies, specifically the kidneys, lungs and brain increase their production of a hormone called erythropoietin, commonly known as EPO. This hormone signals the body to increase its production of red blood cells in the bone marrow. Red blood cells contain oxygen binding hemoglobin proteins that deliver oxygen to the body’s tissues. Thus, more red blood cells equal more oxygen-carrying capacity. In addition to increasing the ability to carry oxygen, our bodies also adapt on a cellular level by increasing the efficiency of energy-producing biochemical pathways, and by decreasing the use of oxygen consuming processes2. Furthermore, the response to chronic hypoxia stimulates the production of growth factors in the body that work to improve vascularization2, thus, increased ability for oxygenated blood to reach its destination. 

So, how can these things offer health benefit?

To start, it appears that adaptation to continuous hypoxia has cardio-protective effects, conferring defense against lethal myocardial injury caused by acute ischemia (lack of blood flow) and the subsequent injury caused by return of blood to the affected area3. The exact mechanism of how this occurs is not well understood, but it seems that heart tissue adapts to be better able to tolerate episodes of ischemia, making it more resistant to damage that could otherwise be done by decreased blood flow that occurs during what is commonly known as a heart attack. This same principle applied to ischemic brain damage when tested in rat subjects. Compared to their normoxic counterparts, rats pre-conditioned with hypoxia sustained less ischemic brain changes when subjected to carotid artery occlusion, suggesting neuroprotective effects of chronic hypoxia exposure4.

Additionally, it appears that altitude-adapted individuals may be better equipped to combat a pathological process known as endothelial dysfunction5. This process is a driving force in the development of atherosclerotic, coronary, and cerebrovascular artery disease. Altitude induces relative vasodilation of the body’s blood vessels compared to lowlanders2. A relaxing molecule known as nitric oxide, or NO, assists with causing this dilation, and in turn the resultant dilated blood vessels produce more of this compound5. The molecule has protective effects on the inner linings of blood vessels and helps to decrease the production of pro-inflammatory cytokines that damage the endothelium5. This damage is what kickstarts the cascade that leads to atherosclerosis in our arteries. Thus, a constant state of hypoxia-induced vasodilation may in fact decrease one’s risk of developing occlusive vascular disease. 

The topics mentioned above highlight a few of the proposed mechanisms by which chronic hypoxia may be beneficial to our health. However, do keep in mind that there are potential detrimental effects, including an increased incidence of pulmonary hypertension as well as exacerbation of preexisting conditions such as COPD, structural heart defects and sleep apnea, to name a few6. Research regarding the effects of chronic hypoxia on the human body is ongoing, and given its significance to those of us living at elevations of 9,000 feet and above, it is important to be aware of the impact our physical environment has on our health. Dr. Ebert-Santos is avidly involved in organizations dedicated to better understanding the health impacts of chronic hypoxia, and has several current research projects of her own that may help us to further understand the underlying science.

Kayla Gray is a medical student at Rocky Vista University in Parker, CO. She grew up in Breckenridge, CO, and spent her third year pediatric clinical rotation with Dr. Chris at Ebert Family Clinic. She plans to specialize in emergency medicine, and hopes to one day end up practicing again in a mountain community. She is an avid skier, backpacker, and traveler, and plans to incorporate global medicine into her future practice.

Citations

  1. Theodore, A. (2018). Oxygenation and mechanisms for hypoxemia. In G. Finlay (Ed.), UpToDate. Retrieved May 2, 2019, from https://www-uptodate-com.proxy.rvu.edu/ contents/oxygenation-and-mechanisms-of-hypoxemia?search=hypoxia&source=search_ result&selectedTitle=1~150&usage_type= default&display_rank=1#H467959
  2. Michiels C. (2004). Physiological and pathological responses to hypoxia. The American journal of pathology, 164(6), 1875–1882. doi:10.1016/S0002-9440(10)63747-9. Retrieved May 2, 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1615763/ 
  3. Kolar, F. (2019). Molecular mechanism underlying the cardioprotective effects conferred by adaptation to chronic continuous and intermittent hypoxia. 7th Chronic Hypoxia Symposium Abstracts. pg 4. Retrieved May 2, 2019. http://zuniv.net/symposium7/Abstracts7CHS.pdf
  4. Das, K., Biradar, M. (2019). Unilateral common carotid artery occlusion and brain histopathology in rats pre-conditioned with sub chronic hypoxia. 7th Chronic Hypoxia Symposium Abstracts. pg 5. Retrieved May 2, 2019. http://zuniv.net/symposium7/Abstracts7CHS.pdf
  5. Gerstein, W. (2019). Endothelial dysfunction at high altitude. 7th Chronic Hypoxia Symposium Abstracts. pg 11. Retrieved May 7, 2019. http://zuniv.net/symposium7/Abstracts7CHS.pdf
  6. Hypoxemia. Cleveland Clinic. Updated March 7, 2018. Retrieved May 9, 2019. https://my.clevelandclinic.org/health/diseases/17727-hypoxemia
Altitude Science, High Altitude

Watch Out for Flying Discs: How High Altitude Changes Flight

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by Laundon Transue, PA-S

Have you ever played disc golf? Maybe you know someone who has. Or maybe you’ve seen it from a distance. Perhaps you were taking a walk through a park or on a hiking trail and noticed a warning sign: “You Are Now Entering a Disc Golf Course – Watch Out for Flying Discs.” It can be a dangerous sport.

It’s just like golf, but with frisbees. Only instead of putting your ball into a hole in the ground, you throw your disc into an odd looking metal basket situated on top of a pole with a bunch of chains hanging from it. Maybe you’ve seen one such basket on your stroll through the park and thought “What is that thing?” That’s disc golf.

I learned to play this game in the forests and hills of Northern California, close to sea-level. Colorado is home to some of the best disc golf courses in the country, so I was excited to venture out and experience them after moving here. However, I could tell immediately that something was wrong the first time I played a round in Summit County – my discs were not flying like they used to!

How exactly were they flying differently? It was hard to say, I just knew they weren’t flying like I was expecting them to. It was throwing my game off. I’ve learned quickly that life at over 9,000 ft has all sorts of challenges not faced by sea-level dwellers. After a few rounds of disc golf up here and feeling like I had to learn how to play all over again, I wondered if my new high altitude environment had something to do with why my discs were misbehaving.

I set out to better understand the physics behind how discs fly through the air and how altitude affects these characteristics.

A lightweight flying disc traveling through the air is very sensitive to the atmosphere. At sea-level there is increased air density, so flying objects encounter more air resistance. As elevation increases, air density decreases, and there is less resistance in the air for flying objects to encounter. So yes, high altitude does cause flying objects to fly differently, but there’s a lot more to the story when it comes to disc golf.

Disc golf is a challenging game. The goal is to throw a ⅓ lb plastic disc hundreds of feet through the air across rough terrain while avoiding trees, hills, ponds, and eventually land in that odd metal basket, hopefully doing so in fewer throws than it takes your friends.

The fun part is throwing the disc far. Flying discs can travel much, much further than most other objects thrown by hand such as a baseball or football. The world record for throwing a golf disc stands at over 1,100 ft.

The hard part is throwing the disc accurately. Unlike a spherical object, the trajectory of a flying disc is not something easily graphed and calculated in your Physics 101 class. A ball thrown up in the air follows a relatively predictable parabolic path largely determined by the force of gravity acting on the sphere. It goes up, it comes down, easy-peasy.

The force of gravity also applies to a spinning disc as it flies. However, the unique shape of the disc, and the rotational torque (spin) acting on it, makes for a much more complex physics problem to solve. Disc golf is all about solving this physics problem in real time and in the real world.

As an object, such as a disc, flies through the air, it is constantly bumping into gas particles in the atmosphere which gradually slow the disc down until it eventually comes to a stop on the ground, this is wind (air) resistance. Also, the shape of a spinning disc thrown through the air generates lift, similar to the wings of an airplane. This means the air passing around the disc as it’s flying exerts an upward force which keeps the disc aloft longer, and this is why discs can be thrown so much further than a sphere. In summary, the air particles a disc encounters on its flight are responsible for both slowing down the disc due to air resistance, and for keeping the disc aloft due to lift. Fascinating!

Now here’s where it gets really complicated. You see, flying discs do not travel in a straight line. A disc thrown through the air will actually travel in an S-shaped line. If thrown by a right handed player, a disc will spin clockwise when viewed from above. When a disc leaves the golfer’s hand the clockwise spin will cause it to first start to drift to the right, then as the disc slows down it will start to drift back to the left, before finally landing on the ground. This property of flying discs to travel in an S-shaped line is termed stability.

Stability is a result of rotational torque and unequal air pressures generated on opposite sides of the disc. Think about the clockwise spinning disc described above. The left side of the disc (at the 9 o’clock position) is spinning into the wind, in the same vector as the trajectory of the disc. The right side of the disc (at the 3 o’clock position) is spinning away from the wind, in the opposite vector of the disc’s flight. This results in a high air pressure system on the left side of the disc, and a low air pressure system on the right side. Higher air pressure on the left means greater lift on the left. That unequal lift result is a gradual drifting of the disc to the right as it flies, and this is the first half of the S-shaped flight path caused by a disc’s stability.

To understand the second half of stability, we need to introduce another concept called gyroscopic precession. This is another complicated piece of physics, but it’s the same principle that keeps you from falling when riding on a hoverboard, and it’s what allows helicopters to maneuver around in the air. Gyroscopic precession says that if you apply a perpendicular force  to a spinning object, that force will be seen 90 degrees away in the direction of spin from where the force was applied. So if we have a clockwise spinning disc, and we apply an upward force at the 12 o’clock position, the disc will feel an upward force at the 3 o’clock position. Another example would be if we applied a downward force at the 7 o’clock position, then the disc would feel a downward force at the 10 o’clock position.

After the disc has traveled through the air for a bit it will start to slow down due to wind resistance. This means the disc will be moving at a slower velocity through the air, and will also be spinning at a slower rate. Slower speed through the air means less lift force acting on the disc and the disc will start to fall toward the ground. When the disc starts to fall, instead of the front of the disc slicing straight through the air like it did when it first left the golfer’s hand, the directional force of the air starts to push upward underneath the front of the disc. In other words, the disc is falling onto the air while it flies forward, and the air is now applying an upward force against the front of the disc.

So our disc is spinning clockwise, and now there is an upward force applied at the front of the disc (12 o’clock), then according to gyroscopic precession, the disc should feel an upward force at the 3 o’clock position (the right side of the disc). This upward force on the right side of the disc causes it to drift back toward the left until it eventually slows down to the point of landing on the ground.

Okay, that was a lot, let’s put it all together! A golf disc is thrown by a right handed player. The disc starts out flying through the air very fast and spinning at a high rate in a clockwise direction. The fast spinning disc creates higher pressure on the left side than the right due to air resistance. This left side pressure lifts and pushes the disc to the right as it’s flying. The disc starts to slow down and begins to fall, resulting in an upward force of air against the front of the disc. This upward air force produces a gyroscopic force 90 degrees away at the 3 o’clock position. The upward force on the right side of the disc causes it to fly back toward the left while the disc continues to slow and eventually lands on the ground.

Now that we know how discs are supposed to fly and how the atmospheric forces determine a disc’s flight, what changes should we expect to see when playing disc golf at high altitude?

At 9,000+ ft elevation there are significantly fewer gas particles in the atmosphere for discs to bump into during their flight. A disc will have less air resistance to deal with. That means it should fly faster and further, right? Not necessarily.

Remember, the atmosphere not only slows the disc down due to air resistance, it also provides the lift that keeps the disc up in the air for so long. Less gas particles in the atmosphere also mean less lift force.

So do discs fly shorter, further, or the same distance at high altitude? The answer is, it depends. Again, flying discs are a much more complicated physics problem than a flying baseball. Discs may fly further or shorter distances at high altitude compared to sea-level, but it depends on the type of disc, the player, and a whole host of other environmental factors such as specific elevation, temperature, humidity, and the direction of the wind.

What we can say, however, is that discs do fly differently at altitude. The shape of the S-path a disc takes at high altitude will look different due to the reduced air density, and this can spell trouble for a disc golfer who’s expecting their disc to turn right but instead it turns left.

During the first half of the stability S-curve, the disc is normally pushed toward the right due lift pressure created by air resistance. At high altitude less air resistance means less lift pressure generated during this first half of the S-curve, so the disc doesn’t move toward the right as much.

The second half of the S-curve is also changed. As we said before, less atmosphere mens less lift, so the disc will start to fall from its flight path sooner at high altitude. That means the upward air force on the front of the disc that results when it starts to fall will also occur sooner in the disc’s flight. Remember, this is the force that is felt by the disc 90 degrees away on the right side of the disc and pushes the disc to the left for the final part of its flight path.

At high altitudes discs drift less toward the right during the first half of their S-curve, and they begin the second half of their S-curve sooner along their flight path. The result is discs fly not so much in an S-shaped path, but rather a J-shaped, or hook-shaped path.

There you have it, High Altitude Disc Golf in a nut-shell. It was initially very frustrating when I started playing disc golf in Summit County. High altitude disc golf forces you to think about each hole and and each shot differently than you might at sea-level. The thin air changes the game dramatically, but that’s what I love most about disc golf. It’s a game that is virtually impossible to master, constantly challenges you, and can be enjoyed outside in the most beautiful and most extreme environments. Pick out a disc at your local sporting goods store and give it a try.

Acclimation, Altitude Science, Child Growth & Development, Genetics, Health, High Altitude

RSV: The Higher the Altitude, the Higher the Risk

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Respiratory syncytial virus, RSV, is a common disease that predominantly affects infants and children throughout the world. Symptoms include mild fever, runny nose, coughing, and wheezing (CDC, 2021 and is the leading cause of bronchiolitis and pneumonia in children under the age of 1 in the United States. Because of this high risk of lower respiratory symptoms RSV is also the leading cause of hospitalizations within this age group (Sanofi Pasteur, 2021). Testing for RSV is quick and easy. Children under the age of 5 can be tested for RSV with a nasal swab and rRT-PCR test, similar to COVID-19 home tests (CDC, 2021) available at clinics and emergency rooms. . Unfortunately, preventing the spread of RSV and keeping these hospitalization rates to a minimum is more difficult at higher elevations.

One of our patients during admission after being diagnosed with RSV earlier in the day.

Higher elevations affect the body in many ways. The human body physiologically adapts within seconds of exposure to higher altitudes. Respiratory rate increases in order to compensate for the lower amount of oxygen circulating within the body (Scott, 2018). Within days to weeks, the body begins to acclimate to the higher altitude and this hypoxic state by maintaining this increased ventilation rate and increasing the amount of hemoglobin in the body (Scott, 2018). Due to the combination of effects on ventilation and oxygenation, managing respiratory infections like RSV becomes more difficult.

  The correlation between rates of RSV and higher altitudes has been studied more in recent years. It is hypothesized that the physiological changes that the body undergoes at higher altitude predisposes children to respiratory illnesses including RSV (Shi et al., 2015). In one study done in Colorado, the incidence of RSV within the population was higher than those at moderate and lower elevation areas. The rates of hospitalization increased 25% with children under the age of 1 and up to 53% with children between 1 and 4 (Choudhuri et al, 2006). Data shows that as altitude increases, the incidence of RSV increases, with elevations over 2500m considered as a modest predictor of RSV-related hospitalizations. The incidence of morbidity associated with RSV increases with higher elevation as well (Wu et al., 2015). This increased morbidity is attributed to the thick secretions that is caused by the virus. Since infants breathe through their nose until age 3, this collection of mucus causes respiratory issues including pauses in breathing with cyanosis called apnea. With studies showing the increased incidence, hospitalizations, and morbidity of RSV at higher altitudes, diagnoses of RSV should not be downplayed in children living at high altitudes.

Photo of the same patient as above on home oxygen after being discharged from the hospital.

It is important for providers and parents to be aware of the higher risk for more severe disease progression faced by children who reside at higher altitudes. Parents should recognize the symptoms of RSV and practice proper handwashing techniques to prevent the further spread of this disease within the community. Health care providers within these high-altitude areas should consider additional interventions and treatments such as home oxygen or nasal suctioning which may be beneficial to preventing hospitalizations due to RSV. Dr. Chris advises parents with older children in daycare or preschool to consider keeping them home during RSV season (November-April) when they have a new baby in the house. Although it is imperative to properly diagnose and treat RSV to avoid hospitalizations, obtaining a chest x-ray and treating with medications like albuterol or steroids is unnecessary. Ultimately, although RSV is a benign disease to most, in areas of higher elevation, it must be taken seriously order to prevent unfavorable outcomes.

References

Centers for Disease Control and Prevention. (2021, September 24). Symptoms and care of RSV (respiratory syncytial virus). Centers for Disease Control and Prevention. Retrieved April 28, 2022, from https://www.cdc.gov/rsv/about/symptoms.html 

Choudhuri, J. A., Ogden, L. G., Ruttenber, A. J., Thomas, D. S., Todd, J. K., & Simoes, E. A. (2006). Effect of altitude on hospitalizations for respiratory syncytial virus infection. Pediatrics, 117(2), 349–356. https://doi.org/10.1542/peds.2004-2795

Sanofi Pasteur. (2021). Rethink RSV. Retrieved April 28, 2022, from https://www.rethinkrsv.com/

Scott, B. (2018, June 13). How does altitude affect the body? Murdoch University. Retrieved April 28, 2022, from https://www.murdoch.edu.au/news/articles/opinion-how-does-altitude-affect-the-body#:~:text=Many%20people%20who%20ascend%20to,lethargy%2C%20dizziness%20and%20disturbed%20sleep 

 Shi, T., Balsells, E., Wastnedge, E., Singleton, R., Rasmussen, Z. A., Zar, H. J., Rath, B. A., Madhi, S. A., Campbell, S., Vaccari, L. C., Bulkow, L. R., Thomas, E. D., Barnett, W., Hoppe, C., Campbell, H., & Nair, H. (2015). Risk factors for respiratory syncytial virus associated with acute lower respiratory infection in children under five years: Systematic review and meta-analysis. Journal of iglobal health, 5(2), 020416. https://doi.org/10.7189/jogh.05.020416

Wu, A., Budge, P. J., Williams, J., Griffin, M. R., Edwards, K. M., Johnson, M., Zhu, Y., Hartinger, S., Verastegui, H., Gil, A. I., Lanata, C. F., & Grijalva, C. G. (2015). Incidence and Risk Factors for Respiratory Syncytial Virus and Human Metapneumovirus Infections among Children in the Remote Highlands of Peru. PloS one, 10(6), e0130233. https://doi.org/10.1371/journal.pone.0130233

Claire Marasigan is a 2nd year PA student currently studying at Midwestern University in Glendale, Arizona. Claire has lived her entire life in Arizona and went to Grand Canyon University for her undergraduate degree in Biology. Prior to PA school, she was a medical scribe trainer at St. Joseph’s Hospital in Phoenix. In her free time, she loves to cook, try new restaurants with friends, and play with her dog, Koji. 

Acclimation, Altitude Science, Child Growth & Development, Exposure, Health, High Altitude

Kids Living at Altitude are Built Different: How Phenotypic Variations in Pediatric Patients Born at Altitude Help Them Compensate for Their Hypoxic Environment

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One of the phenomena I experienced while caring for pediatric patients in Summit County was the image of a [1] child with an oxygen saturation of 83% who wasn’t in any respiratory distress. This got me thinking: do adaptations in children exposed to chronic hypoxia at altitude prepare them to encounter an episode of acute hypoxia?

It turns out this phenomenon has been studied previously. Children permanently residing at high altitudes exhibit phenotypic variations to help them adapt to their chronically hypoxic environment. According to de Meer, K., et al., for those children living at altitudes greater than 3000m above sea level since gametogenesis, the opportunities for phenotypic plasticity are particularly excellent.

These changes in phenotypic expression have led to both theorized and proven physiologic differences in oxygen uptake, transport, systemic circulation, and consumption, allowing them to overcome the effects of chronic high-altitude hypoxia.

The lower partial pressure of oxygen causes high-altitude hypoxia to those who are visiting from lower altitudes. With less oxygen in the air, increased respiratory effort would be required to maintain the same oxygen levels as those children living at sea level. However, children living at altitude have physiologic increases in ventilation, lung compliance, and pulmonary diffusion, which help negate the need for augmented respiratory effort.

To conserve respiratory rate, increases in lung compliance and tidal volume have been observed in children living at altitude. In one study by Mortola, J. P., et al., lung compliance and tidal volume remained increased even while participants were on 100% supplemental oxygen.      This suggests that this is a permanent physiological adaptation in kids living at altitude.2

Additionally, children living at altitude are more efficient at delivering oxygen to their tissues. An increase in pulmonary diffusion capacity facilitates this improved efficiency. Pulmonary diffusion capacity is determined by the surface area available for diffusion. Assuming all other anatomic variables are the same in highlanders and lowlanders[2] , this increased capacity can only be explained by an increase in the number and size of alveoli.1 To study this possibility, researchers compared the lung volumes and chest dimensions of children exposed to chronic hypoxia at altitude since birth to those of children living at sea level and found that lung volumes and chest dimensions of children residing at altitude indeed were greater.

Despite this opportunity for increased oxygen uptake by the lungs of children living at altitude, the partial pressure of oxygen in their blood is still substantially lower. This decrease in arterial blood oxygen concentration that is associated with hypoxia encourages the kidneys to release erythropoietin, which subsequently stimulates the production of erythrocytes contributing to an increased erythrocyte and hemoglobin concentration in children living at altitude. Elevated hemoglobin concentration leads to a relative increase in arterial oxygen saturation, which compensates for the lower availability of oxygen at altitude.1

Despite the witnessed phenomenon of the ability of children living at altitude to adapt to acute hypoxia, it is still debated whether chronic hypoxemia in this population results in decreased oxygen consumption. New research has concluded that previously observed decreases in oxygen metabolism in newborns at altitude are reactions to acute stress and hypoxia and should not be considered an effect of chronic exposure to hypoxia.1 In other words, the ability of children living at altitude to decrease ventilation during an episode of acute hypoxia is due to a decrease in tissue metabolism only during that event of respiratory stress.

Like most things in life, these advantages do not come without consequences. Humans exposed to chronic hypoxia are prone to pulmonary hypertension; in fact, phenotypic, physiological changes in tidal volume and lung diffusion that improve oxygen uptake contribute to pulmonary hypertension. However, unlike children who develop pulmonary hypertension unrelated to altitude, highland children often present with a less severe clinical picture and fewer irreversible complications.1

Children born and residing at altitude offer a window into a world of medical phenomena that are little understood. The more we know about the physiological differences in this population, the better we can serve them as clinicians.

References

  1. de Meer, K., et al. “Physical Adaptation of Children to Life at High Altitude.” European Journal of Pediatrics, vol. 154, no. 4, Apr. 1995, pp. 263–72. Springer Link, https://doi.org/10.1007/BF01957359.
  2. Mortola, J. P., et al. “Compliance of the Respiratory System in Infants Born at High Altitude.” The American Review of Respiratory Disease, vol. 142, no. 1, July 1990, pp. 43–48. PubMed, https://doi.org/10.1164/ajrccm/142.1.43.

Lauren Thompson is a second-year Physician Assistant Student at Drexel University in Philadelphia. She is here all the way from sunny sea level, Florida, where she got her degree in Psychology with a minor in Biology from Florida State University. She is currently completing her clinical rotation, which has taken her all over the country with her feline and canine companions, Duke and Remi. Before PA school, Lauren worked as a Certified Nursing Assistant at a local hospital and a Medical Assistant at a pediatric specialty clinic. Outside of medicine, Lauren enjoys traveling, spending time with her animals, singing karaoke, playing disc golf, and taking in all of what mother nature has to offer, whether it’s hiking, skiing, diving, or enjoying the beach.

Acclimation, Altitude Science, Athletic Training, Backcountry, Health, High Altitude, High Altitude Training & Fitness, Huts, Hyperbaric Therapy, Mountaineering, Sleep at Altitude

Sleep at High Altitude

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Have you thought of what it would be like living in the mountains year-round? Medical professionals find it is important to look at what living at high elevations can do to the human body. One activity heavily affected is sleep. As mentioned in previous blog posts, visitors often have trouble falling asleep, staying asleep, and feeling rested in the morning. A recent study published in Physiological Reports measured the effects of sleeping patterns at high elevation. The participants experienced a simulated elevation inside a hyperbaric chamber. This mimicked sleeping at elevations of 3000 meters (9,842 feet) and 4050 meters (13,287 ft) for one night and then sleeping at sea level for several nights to establish a baseline for the research participants. Participants exercised for 3 hours in the hyperbaric chamber allowing researchers to observe how the lower oxygen concentrations affected their ability to perform strenuous tasks. The group that slept in a simulated 4050 meter environment had an increased heart rate that was 28% higher and an oxygen saturation 15% lower than the 3000 meter participants. When comparing sleep itself, the group at 4050 meters had 50% more awakening events throughout each night. This goes along with previous research on this blog that states that people who sleep at high altitude complain of insomnia and frequent awakening when first arriving at high elevation.

These numbers increase even more dramatically when compared to participants at sea level. Related symptoms reported during this study showed the incidence of acute mountain sickness occurred in 10% of the participants at a simulated 3000 meters, increasing to 90% at 4050 meters. As mentioned, the average heart rate increases and oxygen saturation decreases as the elevation increases. The baseline heart rate at sea level was 62 beats per minute, increasing to 80 at 3000 meters and 93 at 4050 meters. Ideally health care providers aim to oxygenate vital organs by keeping the oxygen saturation level between 92-100%. The lower the oxygen level the harder it is to keep organs properly profused. Age, health status, and place of residence are taken into consideration when examining study reports. Oxygen saturation at sea level was 98% decreasing to 92% at 3000 meters and 84% at 4050 meters.

As mentioned in a previous post by Dr. Neale Lange, sleeping at high altitudes can be hard due to the frequent awakenings and nocturnal hypoxia caused by the low oxygen levels at higher elevation. This study reiterates these findings with the results of the average oxygen saturation at 3000 meters being around 92%. Dr. Lange also found that sleep apnea was often more prominent and had more negative effects on the human body in environments that were lower in oxygen. This study agrees with that statement finding that people with sleep apnea had twice the hourly awakenings compared to those at higher elevation that did not have sleep apnea. Dr. Lange also pointed out that the contribution of hypobaric atmosphere to symptoms at altitude as opposed to pure hypoxemia is unknown. Frisco, Colorado is at an elevation of 2800 meters. Ongoing research at Ebert Family Clinic including residents and visitors along with laboratory studies such as this one can guide decisions about interventions and treatment to improve sleep and help us enjoy our time in the mountains.

References

  1. Figueiredo PS, Sils IV, Staab JE, Fulco CS, Muza SR, Beidleman BA. Acute mountain sickness and sleep disturbances differentially influence cognition and mood during rapid ascent to 3000 and 4050 m. Physiological Reports. 2022;10(3). doi:10.14814/phy2.15175
  2. Blog post: HOW DO YOU DEFINE A GOOD NIGHT’S SLEEP?:AN INTRODUCTION TO THE SLEEPIMAGE RING, AN INTERVIEW WITH DR. NEALE LANGE

Casey Weibel is a 2nd year student at Drexel University, born and raised in Pittsburgh, Pennsylvania. He went to Gannon University for his undergrad and got a degree in biology.  Before PA school, Casey was an EMT.  He enjoys hiking and kayaking and is a big sports fan. 

Backcountry, Backpacking, Exposure, High Altitude, High Altitude Training & Fitness, Mountaineering

After 21 Years of Hiking at Altitude I Had to Call Rescue

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Another Lesson on High Altitude Health and Safety

Wild animals, storms, avalanches, cold, high altitude pulmonary edema or cerebral edema, falls, fires and injuries are the most common dangers in the mountains. I’ve climbed 19 different mountains in Colorado over 14,000′, and some of them more than once, making for 28 successful ascents. But I called Summit County Search and Rescue Saturday for something I was not expecting: deep wet snow that trapped me less than 2 miles from the trailhead.

A colorful map of lines in red, green and white depicting trails through various mountain terrain.
Summit County trail map

It was a bright, warm day — I had even left my hand warmers at home. My plan was to hike from Miners Creek trailhead in Frisco to Gold Hill Trailhead north of Breckenridge which is about a 6- or 7-mile trip one way. I had hiked from both ends in previous weeks and saw the turn-off had snow and no tracks. I attached my snowshoes to my backpack with plans to turn up towards Gold Hill if there were tracks, and there were.

After 4 miles I was out of the forest on top with gorgeous 360˚ views of mountains. I no longer saw the trail markers or tracks so set out across the open space with my snowshoes sinking into the snow every 10 to 20 feet. The trail maps and GPS on my phone were sketchy, only showing I was very near the Colorado Trail. I turned down a logging road to get out of the wind thinking the snow would be packed. I could see several open areas that I thought would take me to the familiar trails to Gold Hill.

After an hour sinking into deep snow I noticed I had only one snowshoe. I backtracked 100 feet following the tracks to find it, dug at several spots where I had sunk the deepest but never found it. I went back towards the Colorado Trail but could not progress, having to dig my boot out of deep snow several times.  I tried to backtrack in my footsteps but couldn’t get far. I had now covered a mile in an hour and a half, my phone showing I was only 48 minutes from the Gold Hill trailhead.

So I called 911, thinking they could drive a snowmobile up to get me.  Bad news: the vehicle would just sink the same way I was. The 911 operator knew me and the Summit County Search & Rescue mission coordinator Mark Svenson was in touch several times as I waited from 3:17 until about 6 pm when the crew arrived with skis and extra snowshoes. My Blue Heeler Isa and I stayed within one foot of a small pine tree where we found firm footing after rolling through the deep, soft snow. Luckily the sun kept us warm until 5 pm, and I had food and water. My gloves and boots were soaked so my feet were very cold and I tried to keep Isa lying over my legs or feet.  I had a plastic rain shield extension that I could pull out and sit on in a pocket of the backpack that one of my students had gifted me.

The rescuers had water, snacks, dry socks, dry gloves, gators and snowshoes. They had packed down the trail but there were still times we post-holed on the way down. We arrived at the rescue vehicle as darkness fell. Special Operations Sheriff SJ Hamit waited with Mark and other SCSR staff to welcome us. One of the rescuers told me how happy he was that I was still smiling when they arrived!

Summit County Search & Rescue team, Sheriff Hamit on the left, Dr. Chris far right.

What did I learn? Stay out of deep, wet snow even if it means going back the long way. Bring extra socks and gloves. Buy gators.

I was not afraid because I knew they were coming before dark. I do feel exhilarated that I was able to do such a challenging hike without any pain or blisters, that my knees were strong enough to extract my feet from the deep snow so many times, and that Isa was with me to warn if any animals were near and announce when the rescuers arrived.

Christine Ebert-Santos, MD, MPS is the founding physician and president of Ebert Family Clinic in Frisco, Colorado, where she leads high altitude research in addition to running a full-time family practice. Isa is a two-year-old blue heeler and Dr. Chris’s familiar and guardian angel.

Acclimation, Alcohol at Altitude, Altitude Science, Athletic Training, Genetics, Health, High Altitude, High Altitude Training & Fitness, Sickle Cell

Dad, put your clothes on! Unique presentations of altitude illness, a Discussion with EMS director Thomas Resignolo

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After his father-in-law arrived in the mountains, Thomas noticed later that night he seemed intoxicated despite not seeing him drink alcohol. Thomas woke up the next morning to see him reading the paper in nothing but black socks and a black tie. Thomas knew right away he wasn’t drunk, he had high altitude cerebral edema (HACE). HACE is a complication of acute mountain sickness (AMS). HACE can occur from increased pressure in the blood vessels in the brain, leading to fluid leakage and swelling (edema). This increased vessel pressure can result from the lower atmospheric pressure at high altitude1. Breathing in lower atmospheric pressure gives you less oxygen molecules per breath. Thomas estimates that EMS in Summit County see one case of HACE a year. EMS look for two hallmark signs of HACE, altered mentation and ataxia. When EMS arrive to a patient with altered mentation, they have the patient walk heel-to-toe to evaluate for ataxia. If ataxia is present, immediate descent is necessary. Rapid descent is necessary because HACE can progress rapidly. Years ago, Thomas had a patient walk into the emergency department and die within 10 minutes after arrival. Unlike high altitude pulmonary edema (HAPE), descent is the only cure for HACE.

HAPE is a more common complication of AMS. Similar to HACE, edema occurs from the high pressure inside pulmonary blood vessels pushing fluid into the lungs. The high pressure is caused by a rapid vasoconstriction response to hypoxia or low oxygen partial pressures. Luckily, HAPE has a simple treatment, oxygen. Therefore, visitors with HAPE do not need to descend to lower altitude as with HACE. HAPE is much harder to recognize than HACE and EMS is well trained in how to recognize it. Often, headache is the only symptom2. Thomas explains the HAPE protocol for EMS: In the first 20 seconds of arriving, an oxygen saturation is obtained; they obtain vitals in the next two minutes and then start high flow oxygen if the saturation is below 89%; they then listen to the lungs for signs of fluid. EMS does not treat HACE or HAPE with any medications since descent and oxygen are the effective treatments.

So, who is prone to AMS?

Unfortunately, better physical fitness does not protect you from AMS. Thomas reports that athletes with resting heart rates of 40 or below have a difficult time acclimating. Younger age also doesn’t mean easier acclimation. According to Thomas, the best age for acclimation is late 30s/early 40s. Surprisingly, previous hypoxia can help acclimation to high altitude. For example, Thomas reports that smokers have an easier time acclimating because their body is used to having the vasoconstriction response to hypoxia and breathing faster and deeper to get adequate oxygen intake.

But don’t worry, your conditioning wasn’t for nothing. A healthy diet and regular exercise prevents heart disease. Thomas estimates there are about 12 acute MI’s on the ski hill each year. These patients usually have to be transported to Denver for a stent to be placed. Exacerbation of coronary artery disease (CAD) is so common that EMS refers to altitude travel as the “altitude stress test.” This mimics a cardiac stress test in those with CAD, producing chest pain that wasn’t present at lower altitude.

Those with sickle cell disease are at risk of developing sickle cell crisis when traveling to high altitude. The lower atmospheric pressure allows the normal red blood cells to lose their integrity and become sickle. Thomas reports that EMS encounters this every couple months in patients (usually of Mediterranean descent) that present with diffuse abdominal pain with no obvious cause. This pain results from the sickle cells aggregating together and causing an occlusion. The occlusion leads to tissue hypoxia and ischemia3. These patients are transported to the hospital for treatment.

How can mountain tourists avoid AMS?

Thomas’s first recommendation is to take a staggered stop for one night at an elevation of 5,000-6,000ft, like Denver. When arriving to altitude, take it easy the first 3 days: don’t drink alcohol and do light activity. Save the long hike for the end of the trip. Also avoid substances that blunt the respiratory system like alcohol, opioids, benzodiazepines, etc. Prepare by hydrating the week before and keep drinking plenty of water while on the trip. If you have had a previous episode of AMS, you can speak to your medical provider about prophylactic medication to take before arriving at high altitude.

References

1. Hackett PH, Dietz TE. Travel Medicine. Fourth ed. Edinburgh: Elsevier; 2019. https://www-clinicalkey-com.ezproxy2.library.drexel.edu/#!/content/book/3-s2.0-B9780323546966000422?scrollTo=%23hl0000521. Accessed November 22, 2021.

2. Schafermeyer, R. W. DynaMed. Acute Altitude Illnesses. EBSCO Information Services. https://www.dynamed.com/condition/acute-altitude-illnesses. Accessed November 19, 2021.

3. Sheehan VA, Gordeuk VR, Kutlar A. Disorders of Hemoglobin Structure: Sickle Cell Anemia and Related Abnormalities. In: Kaushansky K, Prchal JT, Burns LJ, Lichtman MA, Levi M, Linch DC. eds. Williams Hematology, 10e. McGraw Hill; 2021. Accessed November 23, 2021. https://accessmedicine-mhmedical-com.ezproxy2.library.drexel.edu/content.aspx?bookid=2962&sectionid=252529206

Samantha Fredrickson is currently a student in Drexel University’s Physician Assistant program.

Altitude Science, COVID-19, Health, High Altitude, Pandemic

COVID-19 Mortality Data in High Altitudes

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As the COVID-19 pandemic continues and new strains are being discovered every day, there is a rush in the world of science and medicine to uncover how to best prevent and treat those who have been affected. This is a worldwide problem, not solely isolated in one location. However, because the world is not uniform and environments and terrains people live in differ, are there those who live in certain areas better adapted to fighting off COVID compared to others if they were exposed? There have been rumors that those living in high altitudes (2,500m+) have some risk reduction factors associated with less infection and lower COVID-19-related mortality. One example is that people living in high altitudes have physiological traits such as increased erythropoietin production seen within their tissues that decreases the effects of COVID-19 on the human body.

A study was conducted in Ecuador between March 2020 and March 2021 to find a relationship between altitude and COVID-19 mortality rates. This study compared 221 cantons in Ecuador ranging from sea level to above 4,300 meters. Each canton was categorized as either low, moderate, high, or very high altitudes based on their location. During the one year of study, trends based on all-caused deaths and deaths relating to COVID-19 were collected and recorded. At the end of the study, it was shown that there was a 24% higher mortality rate in cantons located below 2,500m of altitude compared to cantons located above 2,500m of altitude. 1 However, when this was broken down into narrower categories, it was found that cantons located at “high altitudes” reported the second highest mortality rates due to COVID-19 compared to cantons located at “moderate and very high altitude” which reported the lowest mortality rates due to COVID-19. These results were confusing and showed conflicting information. In addition, two studies done in America and Peru showed that altitude had no protective factors against COVID-19 mortality rates, while another study in Peru demonstrated that there were “strong protective effects of altitude” against COVID-19. 2,3,4

Mixed results and debates have occurred regarding altitude and COVID-19 mortality rates since studies in this area have been limited. Multiple factors that were not accounted for in different studies could be the reason why. Overestimation, underestimation, unreported, and undiagnosed cases can greatly affect the statistics. Not accounting for underlying illnesses such as diabetes or cancer in relation to COVID-19 deaths is another factor that can contribute to the discrepancies in the research. Not to mention, there were some obvious reasons that may contribute to low mortality rates due to COVID-19, too. Two being that there may be a lower population density in higher altitudes compared to cities/countries near sea level resulting in reduced spread of the virus and that there may be less chronic conditions with people living in higher altitudes that are not exacerbated when they are exposed to COVID-19.

Ultimately, few studies have been conducted relating COVID-19 mortality rates to people living in high altitudes. A variety of theories were proposed as to the reason why people living in higher altitudes have a lower mortality rate when exposed to COVID-19, but the sample size and methods used to conduct the research led to gaps in the study. These gaps were refuted resulting in starting at square one again. Until there is more research done, and more data is collected, we cannot conclusively say that those living in higher altitudes have a lower mortality rate when exposed to COVID-19 compared to those who live at altitudes below 2,500m. The corona virus continues to evolve every day and is still affecting the lives of millions. If the virus continues at this rate, more research could be done to see if people living in high altitudes have protective factors against the virus. However, the main goal is to find a cure against this virus. This area of study can change how people live, and high altitude environments may be the next location people will want to move to.

References

  1. Ortiz-Prado E, Fernandez Naranjo RP, Vasconez E, et al. Analysis of Excess Mortality Data at Different Altitudes During the COVID-19 Outbreak in Ecuador. High Alt Med Biol. 2021;22(4):406-416. doi:10.1089/ham.2021.0070

2. Cardenas L, Valverde-Bruffau V, Gonzales GF. Altitude does not protect against SARS-CoV-2 infections and mortality due to COVID-19. Physiol Rep. 2021;9(11):e14922.             doi:10.14814/phy2.14922

3. Woolcott OO, Bergman RN. Mortality Attributed to COVID-19 in High-Altitude          Populations. High Alt Med Biol. 2020;21(4):409-416. doi:10.1089/ham.2020.0098

4. Thomson TM, Casas F, Guerrero HA, Figueroa-Mujíca R, Villafuerte FC, Machicado C.             Potential Protective Effect from COVID-19 Conferred by Altitude: A Longitudinal Analysis      in Peru During Full Lockdown. High Alt Med Biol. 2021;22(2):209-224.     doi:10.1089/ham.2020.0202

 Alex Fan was born and raised in Southern California. It was his grandmother who led him on the path towards medicine. In his free time, he enjoys going to the beach, trying new food locations, playing volleyball, and catching up with friends and family. He is currently a Drexel PA Student hoping to work with the underserved community in the near future.